Method of and apparatus for forming stockings and the like



May 10, 1949. H. c. GILLESPIE METHOD OF AND APPARATUS FOR FORMINGSTOCKINGS AND THE LIKE Flled June 1 1945 by m w I N V EN TOR. Mom? 6267:15 m 89 M Qua/r fiesaumcy 05mm role Patented May 10, 1949- METHOD orAND APPARATUS FOR FoaMiNG STOCKINGS AND mm; mm

Henderson C. Gillespie, Moorestown, N. 1., alsignor to Radio Corporationof America, a corporation of Delaware Application June 1, 1945, SerialNo. 597,024

v Claims. 1

This invention relates to a method of and apparatus for formingstockings and the like, and more particularly to a method of andapparatus for shaping stockings and other similar hollow articles ofdielectric material by placing the same upon a suitable form of theshape which the article is to acquire ultimately and causing the articleto shrink thereon under the influence of heat.

Various forms of apparatus of this type have been suggested heretofore.The most common of these is a series of forms upon which the stockingsor the like are mounted and which are then placed in steam chambers,such as autoclaves, for heating the stockings in a moist atmosphere tocause them to shrink onto the forms. This process is generally known aspreboarding or shaping the stockings. As practiced in the prior art, theprocess requires batch handling of the stockings because of thenecessity of handling steam at high pressure, and this constitutes adefinite limitation upon the-speed of production.

It has also been proposed, heretofore, to provide electrically heatedforms in carrying out the pro-boarding process. However, so far as I amaware, such forms are relatively expensive and rather inefficient.

The primary objectof my present invention is to provide an improvedmethod of and apparatus for pre-boarding stockings and other similar,hollow articles, which method and apparatus will not be subject to theaforementioned limitations.

More particularly, it is an object of my present invention to provide animproved method of and apparatus for heating stockings for the purposeof pre-boarding or shaping the same and which will be suitable forconveyor line production methods in place of the steam autoclave methodsheretofore employed.

Another object of my present invention is to provide an improved methodof pre-boarding stockings as above set forth which can be carried outcontinuously.

It is also an object of my present invention to provide an improvedmethod and apparatus for the purpose set forth above which will behighly efficient in use and relatively inexpensive in operation.

In accordance with my present invention, the stocking to be treated isplaced on a form of electrically conductive material and, while wet andstretched, is passed with the form through or past an inductor couplingdevice which is connected to a source of high frequency electricalenergy and which, therefore, induces high frequency current in the formto heat the same. Heat is then transferred by conduction from the formto the stocking to vaporize the water in the form of steam whichaccomplishes the desired shrinking and forming operation. Thetemperature is preferably raised beyond the steaming point to about 265F. By arranging the heatin apparatus so that relative motion is producedbetween each of the electroconductive forms and the inductor couplingdevice, the latter will scan the forms to heat each of them uniformly,whereby uniform heating of the stockings will be effected.

The novel features that I consider character istic of my invention areset forth with particularity in the appended claims. The inventionitself, however, both as to its organization and method of operation, aswell as additional objects and advantages thereof, will best beunderstood from the following description of two embodiments thereofwhen read in connection with the accompanying drawing in which Figure 1is a diagrammatic view of one form of apparatus according to my presentinvention and wherein a single stockin is treated at a time, and

Figure 2 is a similar view of a different form of apparatus according tomy present invention arranged for simultaneously trfeating a pluralityof stockings, as in conveyor line'production methods.

Referring more particularly to the drawing, wherein similar referencecharacters designate corresponding parts throughout, there is shown, inFigure 1, a supporting device I which carries a metallic or otherelectroconductive form 3 on which a stocking 5 is mounted for thepurpose of being shaped, while moist, under the action of heat, thestocking being made of dielectric material which has the characteristicthat it shrinks when subjected to such treatment. The support I and itsform 3 are arranged for movement in a vertical direction by any suitablemeans (not shown) to pass the form 3 through an inductor coupling coil 1which is arranged to surround the form 3 and which is coupled through atransformer 9 to a source of high frequency, electric energy H, such asa vacuum tube oscillation generator operating at radio frequency. Itwill be apparent that, as the form 3 passes through the coil 1, thelatter will scan the form progressively along successive areas thereofand will induce in the form 3 high frequency current for heating thesame practically instantaneously. In turn, the heated form 3 will heatthe stocking 56 i by conduction.

Above the con i is a suitable spray device I! arranged to spray onto thestocking a stream or mist of water which serves to moisten the stockingat a point in advance of the coil 1 in the direction of travel of theplatform and the form 3, as shown by the appended arrow in Figure 1.Thus, when the stocking is heated, the moisture therein is also heatedand transformed into steam, and this causes the stocking 5 to shrinkonto the form 3 and acquire the shape thereof.

In Figure 2, I have shown an arrangement for simultaneously treating aplurality of stockings in the manner set forth above. In thismodification, there is provided an endless conveyor i5 which carries aplurality of hooks or the like H on each of which may be hung anelectroconductive form 3. The heating inductor in this modificationcomprises two groups of inductor heating elements I! and 2|, theelements of each group being connected in parallel relation electricallywithin the group, and the two groups being connected in series acrossthe secondary winding of the transformer 9. It will be noted that thetwo groups of elements I9 and 2| are also arranged in physically spaced,parallel relation to each other to permit the conveyor i5 to carry theforms 3 therebetween and in inductive relation to each of the inductorelements I! and 2|.

In order to insure uniform heating or the entire area of each of theconductive forms 3, the elements l9 and 2| are preferably made of wavyform and areso arranged that the proximate peaks of waves of adjacentones of said elements meet substantially along a common line. Thus, forexample, considerin the upper and intermediate ones of the inductorcoupling elements l9, it will be noted that the lower peaks I90 of theuppermost inductor element terminate approximately at a line 23 at whichalso terminate the upper peaks |9b of the intermediate element I9.Similarly, the lower peaks |9c of the intermediate inductor couplingelements I! terminate along a line 25 at which also terminate the upperpeaks |9d of the lowermost element IS. The distance between a linepassing through the upper peaks of the uppermost element I8 and a linepassing through the lower peaks of the lowermost element I9 issuflicient to substantially embrace the entire length of the form 3. Theinductor coupling elements 2| are similarly arranged. In the formillustrated in Figure 2, the elements I! and 2| are zigzag. However,they may be arranged in any other wave form. For example, they may beundulating similarly to a sine wave, they may be in the form of sawteeth, or they maybe arranged in any other suitable formation, whetherregular or irregular, so long as they embrace substantially the entirelength of the forms 3. When the inductor elements l9 and 2| are soshaped, they will each progressively scan successive areas of each formto effect the same result as that obtained with the modification ofFigure 1.

In advance of the inductor coupling device I,

2|, there is disposed a substantially U-shaped spray device 21 throughwhich the belt I! carries each of the forms 3 so that the stockings 5carried thereon will be suitably moistened. From the spray device 27,the successive forms and the stockings carried thereby are fed betweenthe two banks or groups of inductor coupling elements l9 and 2 i wherethe forms 3 are heated inductively and the stockings 5 are heatedconductively by the forms. Thus, the stockings are quickly andeconomically shrunk onto the forms 3 to cause them to acquire thedesired shape.

Although I have shown and described two modifications of my invention,it will undoubtedly be apparent to those skilled in the art that manyother forms thereof, as well as variations in the particular onesdescribed, are possible. Moreover, the method herein described is alsosusceptible to variations. Thus, for example, the stockings may bemoistened prior to being placed on the forms 3, in which case the spraydevices I! and 21 may be dispensed with. Also, instead of moving theforms past the stationary inductor coupling devices I or I9 and 2 I, theforms may be held stationary and the inductors arranged for movementrelative thereto in order to effect suitable scanning of the forms.Again, if desired, the inductor coupling elements l9 and 2| may be madelinear and arranged to extend horizontally, in which case the conveyor|5 may be arranged to move along a wavy path whereby to cause the forms3 carried thereby to bob" up and down relative to the elements I9 and 2|as they are advanced therealong. Other changes of like nature will, nodoubt, be apparent. I therefore desire that my invention shall not belimited except insofar as is made necessary by the prior art and by thespirit of the appended claims.

I claim as my invention:

1. The method of pre-boarding stockings with the aid of anelectroconductive closed flat form which comprises placing a stocking onand fully in contact with said form to provide uniform heat conductionfrom the form to the stocking, passing said stocking bearing formsuccessively past a pair of operating stations, moistening said stockingat the first of said stations, uniformly heating said form inductivelyfrom opposite sides with high frequency current to a predetermineddegree at the second one of said stations, and thereafter causin saidheated form to impart heat uniformly to said stocking by conductionthrough said full contact with the form and thereby to expel themoisture therefrom and cause said stocking to shrink onto said form.

2. The method of pro-boarding stockings set forth in claim 1 whereinsuccessive areas of said form and said stockings are heatedprogressively.

3. In apparatus for shaping a stocking, the combination of anelectro-conductive form having the shape said stocking is to acquire, aninductor coupling device for inducing heating current in an associatedpiece of work adapted to be connected to a source of high frequencyelectric energy, said device comprising an elongated conductor ofrecurrently undulating form, and means for bringing said device and saidform into inductively coupled relation and for effecting relative motionbetween said device and said form in a direction substantially parallelto said device while maintaining said device and said form ininductively coupled relation whereby to cause said device to scan saidform and simultaneously induce high frequency heating current in saidform to thereby heat said form, said form then being adapted to heatsaid stocking by conduction to cause said stocking to shrink onto saidform.

4. Apparatus according to claim 3 characterized by the addition of meansfor moistening said stocking at a point in advance of that at which saidform and said device are brought into inductive relation with eachother.

5. In apparatus for shaping stockings, the cum bination of an endlessconveyor, a plurality of electro-conductive forms carried by saidconveyor in spaced relation, said forms each having the shape to beacquired by the stockings, and an inductor coupling device for inducingheating current in an associated piece of work, said device including apair of spaced inductor elements disposed in parallel relation to eachother and between which said conveyor is arranged to feed said forms insuccession in inductive relation thereto along a path parallel to eachof said elements, said elements each comprising an elongated conductorof recurrently undulating form the undulations of which are disposed insubstantially a common plane, said device being adapted for connectionto a source of high frequency electric energy whereby to be effective toinduce in each of said forms a high frequency current for heating saidforms, and said heated froms then being adapted to heat said stockingsby conduction to cause said stockings to shrink onto their respectiveiorms.

HENDERSON C. GILLESPIE.

summons crrnn The following references are of record in the file of thispatent:

UNITED STATES PATENTS Number Name Date ,379,595 Post May 24, 19211,498,222 Woofter June 17, 1924 1,566,500 Northrup Dec. 22, 19251,848,050 Dennis Mar. 1, 1932 1,848,474 Gosch et al. Mar. 8, 19321,926,694 Berger et al Sept. 12, 1933 2,052,010 Bailey Aug. 25, 19362,081,565 Wahl May 25, 1937 2,181,921 Schlup Dec. 5, 1939 2,186,626 DakeJan. 9, 1940 2,276,643 Bates Mar. 17, 1942 2,328,225 Morey Aug. 31, 19432,371,459 Mittelmann Mar. 13, 1945 2,390,559 Sherman Dec. 11, 1945

